viii PREFATORY NOTE 



in wondrous organization quite as in the lily or the pine, — mitosis; 

 and all in the nucleus as required, nucleus but a fraction of the spore ! 

 Say we not well, a chapter but beginning? 



To assist in meeting such inquiry and interest is the purpose of this 

 book. For this edition it has been to the writer's great pleasure and 

 advantage to have the assistance of his colleague, Dr. G. W. Martin : 

 the introduction and general editing of the text is his. By enlarging 

 our field of inquiry, the number of species presented has been greatly 

 enlarged. New plates were needed, — all our plates are new! To the 

 young botanists of our continent and to our contributors around the 

 world, the present volume is especially devoted. May they fare well ! 



T. H. M. 



